The battle is a two part battle. Enuo's first form has three parts: the LHand and RHand use a separate AI script from the main part, and only the main part can be targeted. Enuo's hidden parts effectively allow him to pseudo-triplecast spells. While the hidden targets can still be attacked with attacks that hit random targets, each part shares the same 60,000 HP. The second part of the battle is another 60,000 HP, albeit only with one target.
The first form is vulnerable to Slow and Stop, but with his high Magic Evasion (120%), neither Slow nor Stop spells will ever hit. Slow Cannon from the Cannoneer's !Combine skillset works, as does Deep Freeze's Stop effect if the Necromancer class or !Dark Arts Lv2 have been hacked into the game, though neither will last long due to Enuo's Heavy type.
Upon losing 60,000 HP, Enuo will switch to his second form, losing the hidden arms and Stop and Slow vulnerabilities. Enuo gains inherent Protect and Shell. This is all accompanied with the text "The power of the Void is increasing!"
The most noticeable of his new attacks is Dimension Zero that will likely kill whoever it hits, as it ignores Defense. If the victim survives, the Sap status is added to them.